Screwdriver construction



Nov. 29, 1966 F. G. CLARK SCREWDRIVER CONSTRUCTION Filed Jan. 15, 1965 IPJVENTOR. WK? 4% ATTORNEYS.

United States Patent Ofifice Patented Nov. 29, 1966 3,288,185 SCREWDRIVER CONSTRUCTION Frederick G. Clark, Buffalo, N.Y., assiguor of one-half to Wade Stevenson, Buifalo, N.Y. Filed Jan. 15, 1965, Ser. No. 425,726 3 Claims. (Cl. 145-51) This invention relates to improvements in screwdrivers of the kind having a nest or socket for the heads of screws or other workpieces to be driven.

One of the objects of this invention is to provide a screwdriver of improved construction in which the bit is relatively short and mounted on the screwdriver to be readily removable and replaceable.

In the accompanying drawings:

FIG. 1 is a side view, partly in section, of a screwdriver embodying this invention.

FIG. 2 is a fragmentary view on an enlarged scale of a part of the screwdriver shown in FIG. 1.

FIGS. 3 and 4 are transverse sections thereof respectively on lines 3-3, FIG. 1 and 4-4, FIG. 2.

In the particular emboi-dment of this invention, shown on the drawings, 5 represents the shank of the screwdriver which may be of any suitable or desired construction, that shown having a hexagonal portion 6 adapted to cooperate with a shank-holding mechanism of a power tool for rotating the screwdriver. It will be understood, however, that this shank may be of any other form and may be provided with a handle for manual use.

The shank terminates at its outer end in a recess or socket 8 preferably of non-circular form to receive a correspondingly formed part 9 of the bit 10. Consequently, the bit 10 may be removed out of the socket 8 for replacement with another bit or tool. Any other driving connection between the bit and the shank may be provided.

The outer end of the shank and the bit 10 are enclosed in a finder sleeve 12 which is slidable on the outer end of the shank and is provided at the outer extremity thereof with a recess or nest 14 shaped to accommodate a head of a screw, bolt or the like which has a slot or other recess for cooperation with the outer end of the bit 10.

Within the sleeve 12 I have provided a coil spring 15 which urges the sleeve into its outer position, shown in FIG. 1. This spring bears at one end against a shoulder 16 formed by a portion of reduced diameter in the sleeve 12 and at its other end the spring bears against a shoulder on the bit, which may be formed by a disk or washer 17 suitably secured in fixed relation on the bit 10. The spring 15 acting against the washer and against the sleeve 12 urges the sleeve outwardly or to the left in FIG. 1 and, also holds the bit in engagement with the socket in the shank 5.

In order to limit outward movement of the finder sleeve. 12 I preferably provide the sleeve with an internal groove 20 in which a spring wire 22 is seated. The shank has a part 24 of reduced diameter which forms with the part of the shank of larger diameter a stop shoulder 25. The spring wire 22 during the normal travel of the sleeve moves along the shank part 24 of reduced diameter and engages the stop shoulder 25 when the sleeve has reached the outer limit of its travel, as shown in FIG. 1. Other means for limiting the travel of the sleeve may be provided.

The stop means for the sleeve also make it possible to remove the sleeve from the screwdriver and thus make it possible to remove and replace the bit. For this purpose the internal groove 20 has a diameter slightly larger than twice the cross sectional diameter of the retaining spring wire 22. The unstressed inside diameter of the retaining spring 22 is only a few thousandths of an inch larger than the reduced diameter 24. When these dimensions, which are given by way of example, are employed, the finder sleeve with the retaining spring 22 so dimensioned with relation to the groove in the sleeve and the reduced diameter 24 of the shank, may be removed from the drill by a slight twist and pull on the sleeve in the direction toward the end of the tool. This will expand the spring wire 22 so that it can pass over the shoulder 25 into the position shown in FIG. 2. The sleeve can then be moved to the end of the shank. Similarly, the sleeve can be returned to .its normal position by moving it on the shank in the opposite direction and when the spring wire 22 passes over the shoulder 25 it will again contract into its stop position with reference to the shoulder 25. Any other means for releasably holding the sleeve 10 on the shank of the drill may be employed if desired and it will be understood that the dimensions above stated are greatly exaggerated in the drawings for sake of clarity.

The bits used in connection with tools of this kind are preferably made of a hard tool steel and are consequently relatively expensive. By making the bit of small size as in the construction shown, a considerable amount of expense is saved in the manufacture of the screwdriver. When necessary to provide a relatively large number of bits of different types or sizes for use in connection with the screwdriver, the cost of these various bits will correspondingly reduce the cost of the screwdriver. It is similarly possible to replace the coil spring 15 if this should be desired, or a sleeve 12 of different size or shape may be used in connection with the shank described, without dismantling any of the screwdriver except the the outer end thereof.

It will be understood that various changes in the details, materials and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. A screwdriver comprising:

(a) a rotatable shank having a polygonal socket at one end thereof,

(b) a bit removably secured in said socket and having a corresponding cross sectional configuration on its socket engaging end,

(c) a finder sleeve slidably mounted on the end of said shank and having an internal shoulder,

(d) a shoulder on said bit,

(e) a spring interposed between said shoulders to simultaneously urge said sleeve outwardly of said bit and said bit into engagement with said shank,

(f) and stop means limiting outward movement of said sleeve.

2. A screwdriver according to claim 1 and including a split spring retaining ring mounted within a groove in said sleeve, and a shoulder on said shank which said ring engages to limit outward movement of said sleeve.

3. A screwdriver comprising:

(a) a rotatable shank having a polygonal socket at one end thereof,

(b) a bit removably secured in said socket and having a corresponding cross sectional configuration,

(c) a finder sleeve slidably mounted on the end of said shank and having an internal shoulder,

(d) a shoulder on said bit,

(e) a spring interposed between said shoulders to simultaneously urge said sleeve outwardly of said bit and said bit into engagement with said shank,

(f) stop means limiting outward movement of said sleeve and including,

, 3 4 (g) a split spring retaining ring mounted within a References Cited by the Examiner gmove in said Sleeve, UNITED STATES PATENTS' h h l h h h a s 011 der 0n l s nk W 10 n nng g g 2782823 2/1957 Williams 145 51 to limit outward movement of said sleeve, when said ring is contracted, and

(i) said ring being expansible to enable the same to pass over said shoulder to remove said sleeve from WILLIAM FELDMAN Prlmary Examiner said shank. R. V. PARKER, JR., Assistant Examiner.

5 2,829,685 4/1958 Mitchell et a1. 

1. A SCREWDRIVER COMPRISING: (A) A ROTATABLE SHANK HAVING A POLYGONAL SOCKET AT ONE END THEREOF, (B) A BIT REMOVABLY SECURED IN SAID SOCKET AND HAVING A CORRESPONDING CROSS SECTIONAL CONFIGURATION ON ITS SOCKET ENGAGING END, (C) A FINDER SLEEVE SLIDABLY MOUNTED ON THE END OF SAID SHANK AND HAVING AN INTERNAL SHOULDER, (D) A SHOULDER ON SAID BIT, 